Apparatus for cracking hydrocarbons.



J. W. COAST, JR.

APPARATUS FOR CRACKING HYDROCARBONS. APPLICATION FILED MAR.2I. 1917.

1,291,414. Patented Jan. 14,1919.

iii/7W6 67/ 9/7867? UNITED sTATEs PATENT OFFICE.

JOHN W. COAST, JR., OF TULSA, OKLAHOMA, ASSIGNOR TO THE PROCESS COMPANY, A. CORPORATION OF MARYLAND.

APPARATUS FOR CRACKING HYDROCARBONS.

' a citizen of the United States of America, a

resident of Tulsa, in the county of Tulsa, State of Oklahoma, have invented certain new and useful Improvements in Apparatus for CrackingI-Iydrocarbons, of which the following is a full, clear, and exact description reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to improvements in apparatus for cracking petroleum hydrocarbons, one of the objects being to rotect cracking stills from the injurious e ects of coke-forming substances which tend to ac-.

cuinulate on the hottest parts of the stills. This feature of the invention increases the efliciency of a cracking apparatus by circulating the coke, or carbon, away from the point at which heat is transmitted to the still, thus permitting the heat to be transmitted freely from the still to the oil, at the same time avoiding the danger of overheating the metal of the still, and allowing the apparatus to remain in service for a considerable period of time. I attain this object by permitting the liquid to overflow from one cracking still to another and removing the coke-forming substance from the overflowing liquid. Th1s coke-forming substance consists of heavy fractions which drop by gravity to the lower portion of the liquid in the still, and the overflowing liquid is therefore, preferably, conducted from the lower portion of one still, through a coketrap, and then into another still.

Figure I is a diagrammatical view, partly in section, of a cracking apparatus embodying the features of my invention.

Fig. II is a diagrammatical perspective view, showing a battery of cracking stills connected by overflow conductors.

Fig. III is an enlarged vertical section illustlatlng one of the coke-traps.

To illustrate the invention, I have shown a battery of cracking stills designated 1, 2, 3 and 4. respectively, each cracking still is arranged above a heating chamber 5 and connected by means of an air cooled vapor pipe 6 to a reflux condenser 7, said condenser 7 being connected by means of a vapor ipe 8 to a water cooled condensing coil 9, rom

which the low boiling point product is re- 66 covered. Each vapor plpe 8 is preferably Specification of Letters Patent.

Application filed March 27, 1917. Serial No. 157,630.

provided with a valve 10 for regulating the pressure.

The apparatus I have shown is particularl y adapted for use in cracking high boiling point products of distillation, such, for example, as the distillates or residues resulting from the distillation of petroleum. The pressure in the battery of stills is preferably greater than 50 pounds per square inch, and the temperature of the contents of the stills preferably ranges from about 600 F. to 800 F. Heat is transmitted directly through the bottoms of the stills so as to vaporize and crack the oil contained therein. The heavy coke-forming fractions drop by gravity in the liquid and tend to accumulate on the hot still bottoms.

The object of this invention is to remove the coke-forming fractions by causin the liquid to overflow from the bottom 0% one still, through a coke-trap and theninto another still, the coke-forming substance being thus circulated from the lower portion of the first mentioned still and deposited in the coke-trap. The oil to be cracked isto the still 2 by means of a pipe 14. The

liquid overflowing from the still 1, passes out through the pipe 12, and is discharged into the lower portion of the coke-trap 13.

The heavy coke-forming fractions are permitted to accumulate at the bottom of the coke-trap, and the lighter liquid overflows from the upper portion of the coke-trap and circulates into the still 2; A large percentage of the heavy, coke-forming substance is thus conducted to the coke-trap 13, where it will not in any way injure or affect the cracking apparatus. The coke, or tarry, coke-forming substance, may be removed from the trap 13 by opening a valve 15 in the discharge pipe 16.

The li uld overflowing from the lower portion of the still 2, passes through a pi e 12 and into a coke-trap 13, the relative y light liquid being permitted to overflow from said coke-trap 13 through a pipe 14' and into the still 3. The stills 3 and 4: are

connected by means of an overflow pipe 12', a coke-trap 13 and an overflow pipe 14:. The overflow conductors place the difi'erent stills in free communication with each other, and a uniform pressure is therefore maintained in all of the stills. This pressure is also maintained in the coke-traps and overflow pipes. All of the overflowing liquid must circulate through a coke-trap, wherein the heavy coke-forming substance will drop by gravity instead of passing from one still to another.

I claim:

In an apparatus for cracking hydrocarbons, horizontal cylindrical pressure stills,

naet eie means for heatingthe bottoms of said pres sure stills, a coke-trap, an overflow pipe leading from the lower portion of one still to said coke-trap, and an overflow pipe lead ing from the upper portion of said coketrap to the other still, said overflow pipes and coke-trap being in free communication with both stills so as to equalize the pressure therein, at the same time permitting liquid to be cracked and coke forming matter to overflow throu h the first mentioned overflow pipe to said coke-trap.

In testimony that I claim the foregoing I hereunto aflix my signature.

JOHN w. CUAST, JR. 

